售

Bottom 口 - the mouth radical, the indexing component. Selling happens through the mouth: calling out wares, naming a price, closing the deal. 售 means 'to sell, deal in, dispose of' (出售 to put up for sale, 售货员 shop assistant). The mouth-radical anchor makes the speech-act side of commerce visible.

Top 隹 - pictograph of a short-tailed bird - supplies the sound. zhuī shifts to shòu through a long but attested phonetic family (售 historically related to 雠 'to pay back, requite'). Faint semantic colour: a transaction is like a bird calling out across a market for an answer.